Construction of internalcombustion engines



Oct. 14, 1947. E. P. PAXMAN 2,429,106

CONSTRUCTION OF INTERNAL-COMBUSTION ENGINES Filed Oct. 4, 1943 '3 Sheets-Sheet 1 In uentor Maw Oct. 14, 1947. E. P. PAXMAN CONSTRUCTION INTERNAL-COMBUSTION ENGINES Filed Oct. 4, 1943 SSheets-Sheet 2 A ttorneyS Oct. 14, 1947. E. P. PAXMAN CONSTRUCTION OF INTERNAL-COMBUSTION ENGINES 3 Sheets-Sheet 3 Inventor PM By G m. A tlorney:

Filed Oct. 4, 1943 Patented Oct. 14, 1947 CONSTRUCTION OF IN TERNAL- COMBUSTION ENGINES Edward Philip Paxman, Colchester, England Application October 4, 1943, Serial No.

In Great Britain July 14, 1942 6 Claims.

This invention relates to internal combustion engines and has particular reference to the mounting and housing of a cam shaft and its associated parts. Hitherto it has been the practice to dispose the cam shaft in an extension of the crank case or cylinder block which entailed highly skilled workmanship in assembly owing to the involved machining operations and the necessity for accurately aligning a large number of co-operating parts and the object of the present invention is to simplify the general construction of the engine, expedite assembly and render the cam shaft and parts operating in conjunction therewith more easily accessible than in former constructions,

According to the present invention the cam shaft instead of being housed within an extension of the crank case is mounted in a cam box formed as a separate component and adapted, when the cam shaft, cam rockers and their associated parts have been operatively assembled to be placed in position as a unit adjacent the cylinders whose valves are controlled by the cam shaft.

According to the preferred form of the invention a cam shaft mounting for an internal combustion engine comprises a cam box formed as a separate component and providing bearings for a cam shaft and a rocker shaft both extending through the length of said cam box which is provided with a cover adapted to support a fuel pump and other components in such manner that the complete assembly can be placed in position upon and fixed to an engine crank case.

Reference will now be made to the accompanying drawings in which- Fig. 1 is a side elevation of a complete cam box assembly,

Fig. 2 is a cross section taken on the line IIII of Fig. 1,

.Fig. 3 is a longitudinal sectional elevation of the cam box, r

Fig. 4 is a plan of the cam box and Fig. 5 is a cross section taken on the line V-V of Fig. 3.

.The construction illustrated shows a preferred application to internal combustion engines of the kind wherein two banks of cylinders A are disposed in mutually inclined positions upon a common crank case B.

The space between the two banks of cylinders is utilised for mounting a cam box which consists of a closed casing I having a detachable cover 2 and of considerably greater length than height or' width. The interior of this cam box embodies a number of transverse webs 3 and the cam shaft 4, the rocker shaft 5 and cam rockers 6 are all as sembled within the said cam box before it is operatively positioned between the cylinder blocks.

Below the closed casing I and formed integral therewith is a supporting structure which consists of a hollow box-like member 1 with perforated Walls and base as shown in Figs. 3 and 5 and whose base rests upon a horizontal joint face 8 formed upon the upper central portion of the engine crank case B. The cam box is adapted to be fixed in this position by means of long bolts cover of the crank case.

cover and casing by interposing packing material I5 between them. The cover 2 is also provided with apertures l6 through which pass push rods 11 whose function is to transmit the movements of the cam rockers 6 to the valve rockers in the cylinder heads.

The cam shaft 4 is provided at one end with a pinion l8 through which the drive is transmitted from gearing operated by the crank shaft, the said pinion 18 being housed in a casing l9 bolted at 20 to the end of casing I and cover 2 and having its lower portion connected to an end the cam shaft carries a bevel gear 2| through which a governor mechanism is driven, this mechanism being supported upon a casing 23 which encloses the bevel gearing and is bolted at 24 to the adjacent end of box cover 2 is also formed with seating surfaces 23 (Fig, 3) on which fuel pumps 26 are adapted to be supported, these pumps being secured in position by means of bolts 21 engaging sockets 28 in the cover 2.

Owing to its length the cam box is conveniently I formed in two parts bolted together at 29 as shown in Figs. 3 and 4. The mid portion of the cam shaft carries a gear wheel 30 situated immediately beneath an aperture 3| in the cover 2 through which projects a driven gear 35 engaging the gear wheel 30, the said driven gear being he upper portion of the crank The opposite end of the casing I. The cam components on other parts of the engine housing.

or crank case is avoided.

The cam shaft rotates in lubricant contained in the base of casing '1 which is supplied from, lubricators 31 mounted on the two endbearings,

of the rocker shaft and connected to the engine lubricating system. The rocker, shaft is hollow, and is in communication with the lubricatorsB'I, the rocker shaft having ports at intervals .inits length which communicate with ports 38 through which lubricant is conducted to the bearings-J1 and passages 39 whereby the cam shaft bearings are lubricated.

the particular illustrated the rocker shaft is constructed. in two. separate sections divided by the aperture 3 l. The cain shaft is also formed in two sections united bolts M] which fix thegear Wheel 30, in position around two flan'gesjon the adjacent ends of the camshaft sections. I The arrangement above described possesses nu-' merous advantages, all of which assist in expediting and simplifying assembly. .Forexample, the entire cam box assembly with its superimposed engine components can be completed as an inde-. pendent entity and simplylowered into operative, position between the. detailed assembly, shaft andseatings for are formed by straight line boring or. operations through the transverse Webs .3 of the cam box and no skilled alignment of bearingsis necessary but only the mounting and fixing of bushingsfor the rocker shaft bearings.

Although the invention the bearings for the cam the rocker. shaft. bearings typev which may be constructed according to our concurrent application No. 9779/42 and provided with acra-nk case according to our concurrent ap plication No. 9780/ l2, the'invention is not limited to such apiilioation but can be adapted to engines of the straight line type. I claim: A c bustion engine having'a tually. inclined. banks thereon, comprising an.

shaft mounting for an internal cornf, cyl nd rs m u d. elongated cam box. hav-v ing' a flat base for mounting'on the top: of the en: gine crank case between the banks of cylinders, and having a separately formed cover on its top, portionslof the top of the box sloping downwardly and laterallyfrom the sides of the cover and provided with series of longitudinally spaced per:

forations, a camshaft mounted in thelower per; 7 a, rockershaft mounted in box-toreceiveandactuate valvepush rods.

ZQIn an' internal combustion engine having a:

crankcase, an elongated cam box formed as a arrangement described and.

the banks of cylinde'rsA. In

equivalent 7 crank caseand two. mu-

with the respective sides of has been' particularly described in connection with an engine .of the V mounted.

a surface thereon formed .irn ny t intGIV S in file of this patent:

component separate from the engine, a cam shaft and a rocker shaft mounted in and extending throughout the length of the cam box, a cover for the cam box formed separately therefrom for mounting thereon and having means for supporting an engine accessory on the top thereof, means for securing the cover to the cam box and for securingsaid accessory on the .top of the cover for placing of the complete assembly of cam box, cover and accessory as a unit in position on the crank case, and means for securing said assemblyin place on the crank case.

3. In an internal combustion engine as defined inclaim2, including a gear on said cam shaft, and a gear carried by said cover and operatively engag eable with said gear on the cam shaft when said cover is mounted on said cam box for driving said accessory.

4. In an internal combustion engine having a crank case and two mutuallyinclined banks of cylinders mounted thereon sets of valve push .rods divergently inclined relatiyielyto. the crank case, a cam box formed as a component separate from.

casebetweenthe banks 'of cylinders, relatively superposed cam; and rocker shafts ,mounted within the cam box and extending longitudinally thereof, and sets of rockers verging lat tions ofthe sets of rockers engaging the respective:

,5. In, an internal combustion engineas defined inclaim .4, wherein said rocker shaft is mounted.

in superposed position. above said camshaft, and the}upper ends of said rockers aremounted on arevmovable inpppositely inclined directions to operate saidrespective setsof push rods, S. In an internal combustion engine as webs provided with sets of lower and upper longitudinally aligned bearings, n which said. ca m shaft and said rocker shaft respectively are nnWARD PHILIP PAXMAN.

essages ar The following references are of record in UNITED STATES P TENTS.

Number Name -Date 1 1,832,964 Vincent Mar. 9, 1920 1,424,428 Vincent Aug. 1, 1922 1,900,587 Schutzniedrig Mar. 7,1933 1,427,190 Brown Aug 29, 1922 2,001,866 Caminez May 21, 935 1,660,599 Davenport Feb. 28,1928

1,918,199 Gosslau June 6, 1933 2,Q4 0 ,84 7 Hasselman .May 19, 1936, 1,293,712 Church-2, Feb.,11, 1919v 1,5oo,1 e VanRanstQ July 3, 1924 1,293,279 Wilbee Feb. 4, 1919 FOREIGN PATENTS Number- Country M Date 7 wanwed n 1 4 351,897 Germany 1922 and havingvalves and...

the engine and having to seat on the crank.

sides of the cam shaft for actuation thereby defined in claim 4, wherein said cambox is formed in; its length with transverse I the k 

